Alkylation process



Patented June 11, 1940 2,2,194 ALKYLATION raocass Eldon a. Stahly and Erwin M. Hattox, Baton Rouge, La., assignors to'Standard Oil Development Company, a corporation of Delaware No Drawing. Application November 25,1938,

SerialNo. 242,215

1-: Claims. (cl. 196-10) This invention relates to improvements in the process of alkyl'ation oi paraiilns and pertains, more particularly, to the production of saturated hydrocarbons boiling within the motor fuel boil- 5 'ing range.

It has heretofore been proposed to produce such hydrocarbon mixtures by polymerization of,

normally gaseous mono-olefins followed by bydrogenation of theolefinicpolymers to produce a saturated inotor fuel. These polymerization reactions have been carried out using HaPO4, H2804 or mixtures of these two acids. It is known to react a mixture containing isobutane and isobutene in the presence of aluminum chloride and hydrogen chloride to produce saturated branched chain alkylation products for incorporation in gasoline. It is also known to carry out this type of reaction in the presence of concentrated suluric acid. Not only has it been possible to alkylate isobutane with normally gaseous monoolefins, but it is known to alkylate such isoparaffins with the polymers of such olefins, that is,

the dimers, trimers, etc., using highly concentrated sulfuric acid as the catalyst.

It is anobject of the present invention to producean increased yield of motor fuel, particularly as to constituents having a high octane number and boiling within the gasoline range, by alkylating mixtures containing isoparaflins and monoolefins either in the form of monomers or polymers in the presence of novel alkylation catalysts.

It is a further object of the present invention to produce an increased yield oi motor fuel, particularly as to octane constituents, boiling within the gasoline range and having an unexpectedly high octane value. p

It is a still further object of this invention to produce greater quantities of aviation -fuels by the reaction of isobutane with isobutylene polymers or copolymers with normal butylenes rather than resorting to straight polymerization followed by the conventional hydrogenation reaction.

It has been proposed and found to be highly feasible to react paraffinic hydrocarbons with olefins to produce saturated hydrocarbons boil ing within the desired motor fuel range. This.

reaction has been denoted as alkylation. It is readily apparent that'a saturated branched chain normally liquid paramn may be produced direct ly by the alkylation of a normally gaseous branched chain paraifin, for example, isobutane, by treating such a compound with a normally gaseous mono-olefin without the necessity of including a hydrogenation treatment in the process as would be the case in using a polymerization process; An alkylation process has advantages in that gaseous reactants, ordinarily burned as gas for heating purposes, are reacted to produce more useful products. Large supplies of field butanes, refinery C4 cuts, cracking l coil gases, gases from debutanizer "units, etc., afford highly desirable sources or supply of the reactants used. However, it is to bedistinctly understood that the invention is not limited to .any particular source of supply of the reactants. 10

It is only essential that an isoparaflin from any suitable source be contacted with-a mono-olefin from any suitable source, in the presence of the novel catalysts.

In general, it may be said that to accomplishthe objects of the invention, it is a feature of the h present invention to carry out the reaction under optimum reaction conditions in the presence of thenovel catalysts. The reaction is preferably carried out at temperatures ranging from beso tween about 0 F. and 120 F., under pressures ranging from about 0 lbs/sq. in. gauge to about 1200 lbs/sq. in. gauge. The reaction time may ,be between about 0.5 and about 3.5 hours. In

general, and within limits, the longer the re- 25 action time, the more completely saturated the final product becomes.

As reactants, it is desirabieto use isobutane, isopentane, and similar low'b'oiling isoparafllns v as the parafllnic constituents of the reaction mixture, although higher boiling paraflins of six and sevenlcarbon atoms per molecule may be employed. As the olefinic reactant, ethylene, propylene, 'n-butylenes, isobutylene, and similar normally gaseous hydrocarbons are particularly de- 35 sirable. In place of the 'monomeric'mono-olefins, it is desirable to use dimers, trimers, tetrainers, etc., and higher polymers of these mono-oleflns, the co-, crossand inter-dimers, trirners, tetramers, etc., and analgous condensation products of 40 these mono-olefins. It is an" essential, in the practice of the invention, that the feedstock contain at least one isoparaffin boiling below the boiling point of the desired final product fraction and that the feed 45 catalysts and the reactants. In the case'of batch should be placed under suflicient pressure to keep them in a liquid state since they are then more easily continuously fed and dispersed into the reactor, containing one of the novel catalysts, by means of jets, porous thimbles, turbo mixers, etc.

No theoriesare advanced as to the mechanics or chemistry of operation, but it is possible that in 95% concentrated sulfuric acid the phosphorus pentoxide reacts to a certain extent with any water present in the sulfuric acid, thereby form-' ing a small quantity of phosphoric acid. However desirable such a phenomenon may be is not known. It is known, however, that a mixture The product may be continuously withdrawn of phosphoric and sulfuric acids, or phosphorus from the top of the reactor. pentoxide alone, gave extremely small, if any,

It has also been found that higher yields are amounts of alkylation products. possible, particularly so in the continuous process Experimental evidence points to the theory operation, if the 09+ (heavier condensation) that the mechanism of the alkylation reaction products are at least partially returned to the involves theintermediate formation of polymers original reaction zone after first being separated or copolymers by the mono-olefins followed by from the C5-C5 products desired. Also, any un-. the degradation of these higher polymers and reacted reactants or light fractions may be recopolymers into an active or nascent state which turned to the original alkylation zone. permits their reaction with the paraffi'ns present. The chief novelty of the invention lies in the The same mechanism appears to hold true where discovery that catalysts composed of an oxide the reaction occurs between a preformedpolyof an element of group V of the periodic system mer or copolyrner and a paraffin. It is to be and a concentrated sulfuric acid act as new and distinctly understood that the, invention is not unexpectedly useful promoters of the alkylation limited to any theory of operation, and is rereaction; In place of the conventional sulfuric stricted only insofar as indicated by the appended acid alkylation or polymerization catalyst, it has claims. been found that P205, V205, N205, or Asz05, when The following tabulation of data from commixed with concentrated H2804, possess the unparative experiments clearly discloses the unusually valuable ability of catalyzing the reaction expected and unobvious results attained:

Table I Example 1 2 a 4 5 e 1 s 9 157 I30. 0.57 V104 15% P105 15% P205 15% P205 5 17 P905 957 95% a 0 0 Catalyst 0 ill 95? P10 1n.93 in 957 in 957 n 957 111 987 3 H130 msoi mso. mso'i H1501 mso'. also? Grams active cat/100 g. feed 95 e5 11 106 100 94 155 101 Reaction time, hrs. 0. 5-2. 0 0.3-2.3 2. 2 0. 5-2. 0 0. 7-2. 5 0. 7-2. 5 0. 5-2. 5 Temperature, F 15-40 15 15-40 68-80 -110 65-70 gresis. lbs/sq. in. gauge 0 0 29 0 30-35 35-110 45 Weight percent isobutylene... 45.5 19.7 48.6 19.6 38.7 19.6 40 Weight percent n-butylcne l. 0 1. 0 1.0 Weight percent isobutane 54.5 51.5 55.3 65 79.3 51.4 79.4 61.3 79.4 Weight percent diis'obut lene 48.5 44.7 35 gelight fiercent olefin reduct on. 100 99 97 99. 8 98 100 100 f0 1102 a v eight percent on oleflns 120 1 152 170 95 174 150 158 160 172 Br. No 40 13 e 140 13 l 17 1e 15 5 Weight percent sats as 93 o s5 s0 s4 s5 94 45 Weight percent 05 5 6. 5 7. 5 7. 5 2. 9 6. 4 10. 4 Weight percent 05... 7 8.5 7.5 20.8 7 5.7 6.8 8.5 Weight percent C1 4 6.5 -8 w 6 9.6 10.2 7.4 Weight percent 01.. 14 20 as '0 3 42. 7 25. 5 s4. 4- 31 38.9 Weight percent 05 and h vier. 70 58. 5 39 85?. 36. 5 53 47. 4 45 32. 4 Octane number: g 3

C5 fraction. 91. 2 35 g 91. 2 C1 fraction- 90. 6 2 90. 6 0-, fraction 89. 4 I: E 89. 4 Ca fraction. 97 88. 8 90. 5

with the result that saturated octanes may be produced in even greater yields than has heretofore been possible and the octane number of'such a Ca fraction or a C5C5 fraction resulting from such a reaction shows a marked improvement over prior analogous processes and catalysts. The yield of C5Ca product also is materially increased.

Not only single oxides but mixtures-of two or more of these oxides may be added to thesulfuric acid to catalyze the alkylation reaction. Thus a mixture of P205 and V205 in sulfuric acid may be used.-

The catalyst may be prepared by mixing from between about 0.5% and about 20% by weight of P205, for example, into a sulfuric acid solution having a concentration between about 90% and about 108%, preferably 93-98%. After thorough mixing, the new catalyst is used in conventional manner in a conventional H2804 polymerization or alkylation type of apparatus to carry-out the desired alkylation reaction.

Where a range of reaction time has been stated in the above table it is to be understood that the feed was added at 15-minute intervals while the last addition of feed was reacted from .3 to .7 of an hour or that the feed was added continuously over the reaction time, .the last addition being reacted from .3 to .7 of an hour.

In Experiment 1, four additions of isobutylene were made at 30-minute intervals to make a total of 45.3% isobutylene added, and, in Experiments 2, 3 and 6, the'olefin was added at about 15- -minute intervals this resulted in a range of contact time. In Experiment 8 the mixed hydrocarbon feed was added to the acid catalyst at the start of the experiment; difficulty in controlling the temperature was experienced. In Experiment '7, the olefin was added to the isobutaneacid mixture over a period of 80-100 minutes with much better control of temperature.

in Example 1, in which 96% H2801 was used as the catalyst. The Ca content of Example 6 .was 26.5%, using the new catalyst as compared with 14% using H2804 as the catalyst. -The octane number of the Ca fractionin Example 6 was Using a diisobutylene-isobutane feed, Examples 2 and 3 show that sulfuric acid gives 152% yield, on the basis of diisobutylene, of C5 and heavier hydrocarbons, the new catalysts result in 170% 7 yields of C5 and heavier, based on the olefins used, and P205 (Example 4) alone gave no alkylation on the basis of dimer since no substantial amount of diisobutylene reacted. The C8 contents of the product of Examples 2 and 3 were 20 and 38 respectively and the octane numbers of the fractions were 92 and 97 respectively.

The feed used in Examples 5, 7 and 9 was-arefinery Ci-isobutane mixture.

Experiments represented by the data of Examples 1, 2 and 4 were carried out for purely comparative purposes and serve merely to more forcefully bring out the unexpected and unobvious advantages when using the novel catalysts.

In all of the examples, the reaction was conducted in batch operation with thorough mechanical stirring. It is, however, expresslywithin the scope of the present invention to carry out alkylation processes using the novel catalysts in a continuous manner.

The above examples are intended to be but illustrative of the invention and are not to be considered as in any way limiting the scope of the invention.

Thenature and objects or" the invention having been thus fully described, what is claimed as new and useful and desired to be secured by Letters Patent is:

1. A process which comprises alkylating acyclic paraffins containing at least one tertiary carbon atom with mono-olefins in the presence of a catalyst comprising at least one oxide of an element of the fifth group of the periodic system in concentrated sulfuric acid.

2. A process which comprises alkylating acyclic isoparaffins with mono-olefins in the presence of a catalyst comprising an oxide of an element of the fifth group of the periodic system in concentrated sulfuric acid.

3. A process which comprises alkylating an acyclic isoparafiln-mono-olefin mixture in the presence of a catalyst comprising between about 0.5%. and about 20% of an oxide of an element of the fifth group of the periodic system in between about 90% and about 108% sulfuric acid.

4. Process as in claim 3 wherein the process is carried out at temperatures, between about 0 F.

- time is between about 0.5 and about 3.5 hours.

6. Process as in claim 3 wherein the reaction is carried out in a continuous manner.

7. A proce. for the production of saturated liquid hydrocarbons boiling in the gasoline range which comprises reacting a mixture containing at least one low boiling acyclic isoparaflin with at least one .member of .the group consisting of normally gaseous mono-olefins, dimers; trimers, tetramers and higher polymers thereof, and analogous copolymers and cross-polymers thereof in thepresence of concentrated sulfuric acid containing an oxide of an element of the fifth group of the periodic system.

8. Process as in claim '1 wherein the isoparaflin is present in an excess of between about 2:1 and about 30:1 over the amount of olefinic constituents present.

9; Process as in claim 7 wherein the oxide is phosphorus pentoxide and the mol ratio of isoparaffin to olefin is 10:1.

10;Process as in claim 7 wherein the catalyst is between about 93% and about 98% sulfuric acid containing between about 5% and about 15% by weight of phosphorus pentoxide.

ii. In a process of catalytically alkylating acyclic paraffins containing at least one tertiary carbon atom with mono-olefins, the improvement which comprises carrying out the process in the presence of concentrated sulfuric acid containing an oxide of a metal of the fifth group of the periodic system.

12. A process which comprises alkylating a I mixture containing isobutane and isobutylene in the presence of about 90% to about 98% sulfuric, acid containing about 5 to about 15% phosphorus pentoxide.

13. A process which comprises alkylating a mixture containing isobutane and. diisobutylene in the presence of about 95% sulfuric acid containing about 15% phosphorus pentoxide.

14. A process which comprises alkylating a mixture of isobutane and isobutylene in the presence of about 93% sulfuric acid containing about 0.5% of vanadium pentoxide.

15. A process which comprises reacting a mixture consisting of about 20% isobutylene and about 80% isobutane at between about 68 and about -80 F. undera gauge pressure of about 50 lbs/sq. in. for about 2.5 hours in the presence of about 95% sulfuric acid containing about 15% phosphorus pentoxide and recovering from the reacted mixture a. fraction boiling within the desired gasoline boiling range.

16. A process which comprisesreacting a mixture consisting of about 20% isobutylene and about 80% isobutane at between about 65 and about F. under a gauge pressure of about 45 lbs/sq. in. for from about to about 2% hours in the presence of about 98% sulfuric acid containing about 5% phosphorus pentoxide and recovering from the reacted mixture a fraction boiling within the desired gasoline boiling range. 17. A. process which comprises reacting a. mixture consisting of about 20% isobutylene and about isobutane at about 65 F. under a gauge pressure of about 50 lbs/sq. in. for about two hours in the presence of about 93% sulfuric acid containing about 0.5% of vanadium pentoxide and recovering from the reacted mixture a fraction boiling within the desired gasoline boiling range.

ELDON E. STAHLY. ERWIN M. HA'I'IOX.

plgc'LAlmsR-Y 2,204,194.E Zdbn E. Stafilfl arid Erwin M Hattor, Bat'onRou e, La.. A IJk Y LATION PROCESS. Patent dated June 11, 1940. Disclaimer ed January 22, 1944,

by the assignee, Standard Oil Developmqnt Company.

Hereby entrs this disclaimer to claims 1 and 2 f said Lettex s Patent. Gazette February 22,1944] 

